Equity, Share Activity Rollforward (Details) - shares	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Share Activity
Treasury stock, beginning balance (shares)	(255,905,051)
Treasury stock, ending balance (shares)	(262,691,943)
Common Stock [Member]
Share Activity
Common stock, beginning balance (shares)	673,000,000	673,000,000
Common stock, ending balance (shares)	673,000,000	673,000,000
Treasury Stock [Member]
Share Activity
Treasury stock, beginning balance (shares)	(256,000,000)	(240,000,000)
Transactions in connection with stock-based compensation plans (shares)	0	(1,000,000)
Stock purchases under purchase programs (shares)	(7,000,000)	(8,000,000)
Treasury stock, ending balance (shares)	(263,000,000)	(249,000,000)